Method and means for forming pipe elbows



y 29, J. MAROTO 1,960,788

METHOD AND MEANS FOR FORMING PIPE ELBOWS Original Filed Nov. 19, 1930 2 Sheets-Sheet l 3 A9 Z0 a /6 frzvc/zi'onrfojjycf Iva/03v May 29, 1934. J M'ARQTQ 1,960,788

\ METHOD AND MEANS FOR FORMING PIPE ELBOWS Original Filed Nov. 19, 1930 2 Sheets-Sheet 2 Ja ffawofa jy-wwmyw.

Patented May 29, 1934 METHOD AND MEANS FOR FORIVHNG PIPE ELBOWS Jorge Maroto, Chicago, 111., assignor to Taylor Forge & Pipe Works, Chicago, 111., a corporation of Illinois Original application November 19, 1930, Serial No.

496,615. Divided and this 16, 1933, Serial No. 652,001

3 Claims.

This invention relates to the manufacture of pipe elbows from wrought metal, and has to do more particularly with a method of and means for bending suitable lengths of tubing into desired final curvature to form therefrom the elbows.

.One of the main objects of my, invention is toprovide an improved method whereby a length of tubing can be bent quickly into desired curvaio ture so as toform an elbow without undesirable thinning of the tubing at the end portions, particularly' at the inner side thereof. A further object'is to provide improved means for bending the tubing, this means employing dies having rectilineal movement and so related and operated that the bending of the tubing" is accomplished in a relatively short period of time, thus facilitating speed of operation with consequent reduction in cost.- Further objects and advantages of my invention will appear fromv the detail description, v

This application is a division of my co-pending application, Serial No. 496,615, for Method and means for forming 'pipe elbows, filed November 19 1930.

In the drawings Figure 1 is a sectional view through the exterior dies and the, means for operating the -'interior dies, parts being shown in elevation, this view illustrating the first step of my method as practiced by the means illustrated;-

Figure- 2 is a sectional view on an enlargedscale through the exterior'dies and the tubing and associated parts, parts being shown in elevation, illustrating the second step of my method;

Figure 3 is a view similar toFigure 2 illustrating the third step of my method;

Figure 4 is a view similar to Figure 2 illustrating the fourth or final step .of my method.

in manufacturing elbows in accordance with my invention, I provide suitable lengths of tubing of proper diameter and of wrought metal, each length having its ends cut 'on converging diagonal planes. Such a length of tubing constitutes a blank, designated a, from which an elbow is formed. The shorter sideof this tubing.

' forms the inner side or shorter bend of the elbow, and is accordingly termed the inner side of the tubing for purposes of description. The longer side of the tubing forms the outer or longer bend of the elbow and, accordingly, is termed the outer side of the tubing. Inthe means illustratedj'I provide a suitable frame 5 of approximately T shape. "A cylinder application January structure 6 is suitably supported at each end of the head of the frame, and oppositely acting pistons 7 and 8 operate in each, of the cylinder structures. These pistons are oppositely inclined, the pistons'8 converging downwardly and inwardly of the frame. The inner end portions of pistons 8 operate in 'guide sleeves 9 at the lower end of stem 10 of frame 5. A cylinder structure 11 is provided at the upper portion of stem 10 and oppositely acting pistons '12 and 55 13 operate in the cylinder structure 11. Piston 12 is slidably mounted, atits lower portion, through a guide opening provided in a web element 14 connecting the sleeves 9. The pistons 12 and 18 are connected together by a suitable frame 15 and liquid under pressure is admitted to and exhausted from the cylinders of structure 11 for moving piston 12 either upwardly or downwardly, in a known manner. The pistons 7 and 8 are also connected by a suitable frame 16 and are operated by hydraulic pressure in the same manner as pistons'12 and 13.

An upper die 17 is suitably mounted upon the lower end of piston 12, and horn 'dies 18 are mounted upon the inner ends of pistons 8. Each of these dies 18 is provided, at the inner side thereof, with a transverse notch 19 forming a rounded shoulder 20 adjacent the iimer end of the die. -A loweryviiie21 is suitably mounted upon a hydraulic rain or piston 22.

Die 1'7 is provided with a trough-like depression defining a forming surface, this depression being of approximately semi-circular cross-section and being curved lengthwise to conform to the desired final curvature of the inner side of the elbow. 90 Since this die is employed to form the inner side of the elbow, I term it theinner exterior die.

The lower die 21 is provided in its upper face with a trough-like depression of approximately semiecircular cross-section and defining a formving surface for shaping the outer bend of the elbow. Accordingly, I term this die 21 the outerexie'rior die. The horn dies 18 have rectilineal movement toward and away from each other, and each is of circular cross-section and tapers toward 9, its inner end. The inner end of die 18 is flat and a parallel to the direction of relative movement of dies 17 and 21, and the lower portions of these dies are curved to conform to the forming sur'- 1 face of die 21. When dies 18 are fully projected, 1 they are in endwise contact and define, at their lower portions, a continuous curved surface corresponding to the desired curvature of the outer side of the elbow, as in Fig. 2. This curved'surface, provided by the lower portions of dies 18,

face of die 21 for accurately shaping the outer side or bend of the elbow to the desired final curvature.

The blank a is disposed between dies 18 with its shorter side in contact with the lower face of die 1'7, as in Figure 1, and dies 18 are then projected into the blank with their inner ends in contact, as in Figure 2. The blank is then supported by dies 18, in spaced relation to dies 1'7 and 21, the ends of the blank, at the shorter or inner side thereof,- resting upon the shoulders 20.

with the blank thus supported, dies 1'! and 21 are moved toward each other into full closed position.

Die 21 coacts with the horn dies 18 to shape the outer side of the blank to the desired final curvature. Die 1'7 bends the central portion or the inner side of the blank outwardly so as to impart a substantially uniform longitudinal curvature outer exterior die, said dies having relative rectilineal movement toward and away from each other, and oppositely inclined horn dies at opposite sides of and operating between the exterior dies, said horn dies having rectilineal movement toward and away from each other and converging toward the outer die, the horn dies having,

, their outer sides curved lengthwise andbeing adapted for insertion into a length of tubing disconforms to and cooperates with the forming surposed between the exterior dies and through the ends of the tubing, said horn dies being provided at their inner sides with elements disposed to shape the inner side of the tubing about said inner die as the horn dies are withdrawn from the tubing with the exterior dies closed.

2. In means for curving a length of tubing, in combination, an inner exterior die and an opposed outer exterior die, said dies having relative rectilineal movement toward and away from each other, and oppositely inclined horn dies at opposite sides of and operating between the exterior dies, said horn dies gaving rectilineal movement toward and away Irp each other and converging toward the outer die, the'hom -dies having their outer sides curved lengthwise and being adapted for insertion into a length of tubing disposed between the exterior dies and through the ends of the tubing, said horn dies being provided at their inner sides with substantially L-shaped notches defining elements disposed to shape the inner side of the tubing about said inner die 'asthe horn dies are withdrawn from the tubing with the exterior dies closed.

3. The method of curving a length oitubing, which comprises supporting the tubing upon two converging horn dies operable between two opposed exterior dies, subjecting the tubing to transverse pressure between'the exterior dies in the closing thereof. and shaping one side of the tubing to iinal curvature over the horn dies and between the latter and one of the exterior dies, and withdrawing the horn dies from between the exterior dies by rectilineal movement while the latter remain closed and shaping the other'side of the tubing to final curvature over the other exterior die by the horn dies in the withdrawing movement of the latter.

JORGE MARO'I'O. 

